Document Type
Journal Article
Department/Unit
Department of Biology
Title
Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste
Language
English
Abstract
Micro-aeration is known to promote the activities of hydrolytic exo-enzymes and used as a strategy to improve the hydrolysis of particulate substrate. The effect of different micro-aeration rates, 0, 129, 258, and 387L-air/kg TS/d (denoted as LBR-AN, LBR-6h, LBR-3h and LBR-2h, respectively) on the solubilization of food waste was evaluated at 35°C in four leach bed reactors (LBR) coupled with methanogenic upflow anaerobic sludge blanket (UASB) reactor. Results indicate that the intensity of micro-aeration influenced the hydrolysis and methane yield. Adequate micro-aeration intensity in LBR-3h and LBR-2h significantly enhanced the carbohydrate and protein hydrolysis by 21-27% and 38-64% respectively. Due to the accelerated acidogenesis, more than 3-fold of acetic acid and butyric acid were produced in LBR-3h as compared to the anaerobic treatment LBR-AN resulting in the maximum methane yield of 0.27L CH4/g VSadded in the UASB. The performance of LBR-6h with inadequate aeration was similar to that of LBR-AN with a comparable hydrolysis degree. Nevertheless, higher aeration intensity in LBR-2h was also unfavorable for methane yield due to significant biomass generation and CO2 respiration of up to 18.5% and 32.8% of the total soluble hydrolysate, respectively. To conclude, appropriate micro-aeration rate can promote the hydrolysis of solid organic waste and methane yield without undesirable carbon loss and an aeration intensity of 258L-air/kg TS/d is recommended for acidogenic LBR treating food waste. © 2013 Elsevier Ltd.
Keywords
Acetic acid, Butyric acid, Methane production, Micro-aeration, Protein hydrolysis
Publication Date
2014
Source Publication Title
Waste Management
Volume
34
Issue
2
Start Page
363
End Page
369
Publisher
Elsevier
DOI
10.1016/j.wasman.2013.10.038
Link to Publisher's Edition
http://dx.doi.org/10.1016/j.wasman.2013.10.038
ISSN (print)
0956053X
ISSN (electronic)
18792456
APA Citation
Xu, S., Selvam, A., & Wong, J. (2014). Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste. Waste Management, 34 (2), 363-369. https://doi.org/10.1016/j.wasman.2013.10.038